Weibull++ Example 7 - Non-Parametric Life Data Analysis
Background
A group of 55 units are put on a life test during which the units are evaluated every 50 hours. Use the simple actuarial method to determine reliability estimates for each failure time.
Experiment and Data
The results of the test are displayed in the table shown next.
| Start Time | End Time | Number of Failures | Number of Suspensions |
| 0 | 50 | 2 | 4 |
| 50 | 100 | 0 | 5 |
| 100 | 150 | 2 | 2 |
| 150 | 200 | 3 | 5 |
| 200 | 250 | 2 | 1 |
| 250 | 300 | 1 | 2 | 300 | 350 | 2 | 1 |
| 350 | 400 | 3 | 3 |
| 400 | 450 | 3 | 4 |
| 450 | 500 | 1 | 2 |
| 500 | 550 | 2 | 1 |
| 550 | 600 | 1 | 0 |
| 600 | 650 | 2 | 1 |
Analysis
Step 1: Using the New Project Wizard in Weibull++ 7, select to create a Non-Parametric Life Data Analysis Folio, as shown next.
Step 2: Select the Actuarial-Simple data type on the Control Panel. This will format the Data Sheet correctly for your input. Next, enter the data from Table 1 into the Data Sheet, as shown next.
Step 3: Click Calculate to calculate the reliability estimates for the data set, then click Show Analysis Summary to display the results in the Results Panel, as shown next.
Step 4: Next, plot the reliability vs. time, as shown next.
